The invention presented herein relates to copy machines having circuitry for detecting the presence of metal carried by an original sought to be copied and upon this detection of the presence of metal providing a signal for inhibiting operation of the copy machine for making a copy from such original. More particularly, the invention relates to the use of an eddy current or inductive proximity switch as the detector for such circuitry and its use in a copy machine in which an optical scan of an original to be copied is used in making a copy.
Situations exist in government and industry involving security sensitive documents which are kept in areas where personnel having access to such documents also have access to a copy machine. The need for making copies of non-sensitive documents in such situations must be balanced with the need that unauthorized copies not be made of sensitive documents. One solution is to have a copy machine, the operation of which is inhibited when a sensitive document is presented to the machine for copying.